Make this effect in a glass shader, normal map or displacement?
I would definitely go the displacement route. You can achieve what you're looking for rather easily by mixing a couple of Noise Textures - one &quot;Large&quot; and less detailed one for the warped shape of the bottle, and another &quot;Smaller&quot;, more detailed one for the little surface bumps. I inverted the mix and darkened it a little to make the roughness of the Material as well. I mixed the result with white before the displacement to soften the effect and make it more realistic (default &quot;contrast&quot; is often too strong).

Result in Cycles (denoised):

If you're willing to subdivide your model quite a bit (using a subsurf modifier), you can enable true displacement to make the whole bottle warp (shown below with exaggerated effect - 0.4 displacement scale) - make sure to switch to &quot;displacement and bump&quot; or &quot;displacement only&quot; in the material settings (only works in Cycles):